1. Field of the Invention
The present invention relates to a plasma display device, and more particularly, to a plasma display device having an improved dielectric layer in which a maintenance electrode is embedded and a method of manufacturing the same.
2. Description of the Related Art
A general discharging device includes at least a pair of electrodes and discharge is generated when a voltage is applied to the electrodes. As an example of the discharging device, there is a discharge lamp such as a fluorescent lamp, a gas laser generating apparatus, and a plasma display device.
Due to superior display performance such as large display capacity, high brightness, high contrast, and wide viewing angle, the plasma display device is widely recognized as a flat panel display panel having a performance close to a cathode ray tube.
Plasma display devices are classified as a direct current plasma display device panel and an alternating current plasma display panel according to operation principle. Also, the plasma display device is divided into an opposing discharge type and a surface discharge type according to the configuration of the electrodes.
FIG. 1 is a view showing an example of a surface discharge type plasma display device.
As shown in the drawing, a plasma display device includes a substrate 10, an address electrode 11 on the substrate 10, a dielectric layer 12 on the substrate 10 where the address electrode 11 is located, a partition 13 on the dielectric layer 12 for maintaining a discharge distance and preventing electrical and optical cross talk between cells, and a front substrate 16 coupled to the substrate where the partition 13 is located and having maintaining electrodes 14 and 15 in a predetermined pattern on the bottom surface, crossing the address electrode 11. A fluorescent layer 17 is located at at least one side inside a discharge space sectioned by the partition 13. A dielectric layer 18 and a protective layer 19 in which the electrodes are embedded are located on the bottom surface of the front substrate 16. A discharge gas mixed with neon (Ne) and xenon (Xe) is injected into the discharge space.
In the plasma display device having the above structure, driving methods are divided into driving for an address discharge and driving for a maintaining discharge. The address discharge is generated due to an electrical field between the address electrode 11 and the maintaining electrode 14 (80V−(−170V)=250V). At this time, wall charges are formed. The maintaining discharge is generated due to a difference in electrical potential between the maintaining electrodes 14 and 15 disposed at the discharge space where wall charges are formed. The maintaining discharge becomes a main discharge for displaying an actual image.
The maintaining discharge generated due to a difference in electrical potential applied between the maintaining electrodes 14 and 15 becomes weak as time passes. This is because the initial discharge voltage must be over 160 V, in general, since the distance between the maintaining electrodes 14 and 15 is about 80–100 μm in an electrode structure of a conventional surface discharge type AC plasma display panel.
When the initial discharge voltage becomes great, much electrical power is consumed and simultaneously the rated capacity of a driving circuit becomes great. Also, induced potential is generated to an adjacent electrode, which causes cross talk. When the distance between the maintaining electrodes 14 and 15 is narrowed to lower the initial discharge voltage, the electrostatic capacity becomes too large.
Alternatively, the quantity of Xe in the discharge gas is increased to increase the efficiency of discharge. However, since the initial discharge voltage becomes great, there is a limit in increasing the quantity of Xe.
A surface discharge type plasma display device to solve the above problems is disclosed in U.S. Pat. No. 5,742,122. In the surface discharge type plasma display device, as shown in FIG. 2, the thickness T1 of a dielectric layer 23 on an upper surface of a transparent electrode 22 of a first substrate 21 is thinner than the thickness T2 of the dielectric layer 23 corresponding to a bus electrode 24 on and parallel to the transparent electrode 22.
In the above surface discharge type plasma display device, by removing ineffective discharge on the bus electrode 24, the efficiency of light emission can be improved while reducing power consumption and preventing cross talk between pixels. However, since the dielectric layer 23 has a uniform thickness on an upper surface of the transparent electrode, there is a limit in reducing the initial discharge voltage.